1. Field of the Invention
The present invention relates to an operation control device, and more particularly to an operation control device capable of preventing, when operating a joystick knob from a starting position to a terminating position, the joystick knob from going too far even when it is operated in one stroke between the starting position and the terminating position which are spaced considerably apart from each other.
2. Description of the Related Art
Generally, the operation control device is equipped with a manually-operating unit having a joystick knob operable at least in one direction, and when operating the joystick knob from a starting position to a terminating position, there is performed an operation for passing through one or more selective positions located between the starting position and the terminating position of the joystick knob in sequence for shifting. Also, in this sort of operation control device, there is known an operation control device in which when operating the joystick knob from the starting position to the terminating position, in order to determine each of one or more selective positions located between the starting position and the terminating position as well as in order to make a feeling favorable when the joystick knob is operated, a given resistance force is imparted to the joystick knob every time the joystick knob shifts to the selective position.
In addition to this, of the operation control devices, there is also known a so-called operation control device for character selection in which different characters and symbols are allotted to a plurality of selective positions respectively where an operation using the joystick knob can be performed, and when the joystick knob is operated at any of the selective positions, a character allotted to the selective position is selected.
FIG. 3 is a block diagram showing an example of structure of the principal portion of the known operation control device for character selection.
As shown in FIG. 3, this operation control device for character selection includes: a manually-operating unit 31 equipped with a joystick knob 31a operable in an X-direction and a Y-direction which cross at right angles; a first knob displacement detector 32a combined with the base of the joystick knob 31a, for detecting an amount of displacement and direction of displacement of the joystick knob 31a in the X-direction to generate knob displacement information in the X-direction corresponding to the detection result; a second knob displacement detector 32b for detecting an amount of displacement and direction of displacement of the joystick knob 31a in the Y-direction to generate knob displacement information in the Y-direction corresponding to the detection result; a displacement amount operating unit 33a for operating an amount of displacement of knob operation in the X-direction and in the Y-direction separately through the use of X-direction knob displacement information and Y-direction knob displacement information which have been supplied; a force amount operating unit 33b for operating an amount of digital force in the X-direction and in the Y-direction separately through the use of the amount of displacement of knob operation obtained by the displacement amount operating unit 33a; a controller (CPU) 33 equipped with an internal memory 33c for temporarily storing knob position information and the like when the operation of the amount of displacement of knob operation and the amount of force is set; a digital-to-analog converter (D/A converter) 34 for converting the amounts of digital force in the X-direction and in the Y-direction separately determined by the force amount operating unit 33b into amounts of analog force in the X-direction and in the Y-direction respectively; a power amplifier 35 for power-amplifying amounts of analog force in the X-direction and the Y-direction obtained by the digital-to-analog converter 34; and motors 36a and 36b whose driving shafts (no drawing No.) are combined with the joystick knob 31a through a gear mechanism (not shown), for respectively imparting forces based on the amounts of analog force in the X-direction and in the Y-direction to be supplied to the operation of the joystick knob 31a in the X-direction and in the Y-direction.
FIG. 4 is an explanatory view showing an example when indicating characters to be allotted to the operation control device for character selection shown in FIG. 3, indicating an example in which character arrangement mainly consists of the Japanese syllabary characters.
As shown in FIG. 4, a horizontal arrangement character group, for example, each character group of            in the first row is selected at their respective selective positions when the joystick knob 31a is operated in the X-direction, and each horizontal arrangement character in the second to fifth rows is also identical. On the other hand, a vertical arrangement character group, for example, each character group of      in the first column is selected at their selective positions when the joystick knob 31a is operated in the Y-direction and each vertical arrangement character in the second to eleventh columns is also identical. Specifically, if the joystick knob 31a is operated in the X-direction to select each character group in the fourth column,      and the joystick knob 31a is operated in the Y-direction to select each character group in the third row,            the character  selected in both operations is selected. Also, even when other characters than  are selected, the selective positions of the joystick knob 31a in the X-direction and in the Y-direction are only different, and the same selection is performed.
Further, FIG. 5A, FIG. 5B and FIG. 5C are explanatory views showing a state in which, in the operation control device for character selection shown in FIG. 3, a force is imparted to the joystick knob 31a during an operation thereof, and FIG. 5A shows a force pattern and FIGS. 5B and 5C, an operator's feeling of operation.
In FIGS. 5A, 5B and 5C, the abscissa indicates an operating position of the joystick knob 31a in one direction, for example, in the X-direction, and the ordinate indicates a state of a force to be imparted to the joystick knob 31a. The “−” symbol in FIG. 5A represents a resistance force imparted to the joystick knob 31a when the joystick knob 31a is operated in a direction from the character 51 to the character 54 which will be described later while the “+” symbol represents a driving force imparted to the joystick knob 31a when the joystick knob 31a is operated in a direction from the character 51 to the character 54. Conversely when operating in a direction from the character 54 to the character 51, the resistance force imparted is changed to the driving force imparted, and the driving force imparted is changed to the resistance force imparted. The downward portions of triangles in FIGS. 5B and 5C indicate images of the force that the operator feels when operating the joystick knob 31a, and represent the driving force and the resistance force respectively. In this case, a feeling of operation due to an operation in a direction from the character 51 to the character 54 becomes the same as that due to an operation in a direction from the character 54 to the character 51. Also, 51, 52, 53 and 54 represent characters allotted to selective positions respectively when the joystick knob 31a is operated.
The operation control device for character selection constructed as described above operates as follows.
When the joystick knob 31a of the manually-operating unit 31 is operated in the X-direction and in the Y-direction to operate the operating position of the joystick knob 31a to a desired selective position, the first knob displacement detector 32a detects an amount of displacement and a direction of displacement of the joystick knob 31a in the X-direction, and generates X-direction knob displacement information corresponding to the detection result. At the same time, the second knob displacement detector 32b detects an amount of displacement and a direction of displacement of the joystick knob 31a in the Y-direction, and generates Y-direction knob displacement information corresponding to the detection result. Thus, the X-direction knob displacement information and the Y-direction knob displacement information which have been generated are supplied to the displacement amount operating unit 33a of the controller 33. The displacement amount operating unit 33a operates amounts of knob displacement in the X-direction and in the Y-direction separately through the use of the X-direction and Y-direction knob displacement information supplied to supply the X-direction and Y-direction amounts of knob displacement thus separately obtained to the force amount operating unit 33b. The force amount operating unit 33b operates amounts of digital force in the X-direction and in the Y-direction separately through the use of the amount of knob displacement supplied to supply the X-direction and Y-direction amounts of digital force thus separately obtained to the digital-to-analog converter 34. The digital-to-analog converter 34 converts the amounts of digital force supplied into an amount of analog force in the X-direction and in the Y-direction separately to supply the X-direction and Y-direction amounts of analog force obtained to the power amplifier 35. The power amplifier 35 power-amplifies the X-direction and Y-direction amounts of analog force supplied so as to raise it to a predetermined power level, and supplies these amounts of analog force thus amplified to the motors 36a and 36b corresponding thereto. When the X-direction amount of analog force is supplied, the motor 36a imparts such a resistance force and a driving force as shown in FIG. 5A to the joystick knob 31a under operation in the X-direction, whereby such a feeling of operation as shown in FIGS. 5B and 5C is given to the operator. Similarly, when the Y-direction amount of analog force is supplied, the motor 36b imparts such a resistance force and a driving force as shown in FIG. 5A to the joystick knob 31a under operation in the Y-direction, whereby such a feeling of operation as shown in FIGS. 5B and 5C is given.
In this case, when the joystick knob 31a is operated until the operating position thereof reaches a desired selective position to operate an operating switch (not shown) or the like at that selective position, a character allotted to the selective position is selected, and the selected character is indicated within a blank framework provided in the upper portion of the character arrangement of the Japanese syllabary shown in FIG. 4. Next, when the joystick knob 31a is operated until the operating position reaches a desired selective position to operate an operating switch or the like at that selective position, a character allotted to the selective position is selected, and the selected character is indicated next to the former character indicated within the blank framework. Hereafter, the character is also selected in sequence in the same manner to indicate the character selected within the blank framework. When all the characters have been selected and a desired character string has been obtained, the joystick knob 31a is operated until the operating position thereof reaches a selective position where a character “Completed” shown in FIG. 4 is indicated, and when the operating switch or the like is operated at the selective position, the desired character string is transferred to a necessary position for the operation control device for character selection, and it becomes possible to select a new character string again.
In the above-described known operation control device for character selection, in the case where the joystick knob 31a is operated from the starting selective position to a desired terminating selective position in the X-direction and in the Y-direction, if the starting selective position is close to the terminating selective position, when the joystick knob 31a is operated to the terminating selective position, due to a fixed resistance force to be imparted at the selective position, it is possible to stop the operation of the joystick knob 31a at the selective position because an operating force to be applied to the joystick knob 31a during the operation of the joystick knob 31a is low. However, if the starting selective position is away from the terminating selective position, an operation due to a comparatively high operating force is performed so as to ignore a resistance force at a selective position on the way during the operation of the joystick knob 31a. Therefore, the operating force to be applied to the joystick knob 31a becomes great, and when the joystick knob 31a is operated to a desired terminating selective position, the operating force to be applied is greater than a fixed resistance force to be imparted at the selective position, whereby the operation of the joystick knob 31a often fails to stop at the selective position and the joystick knob 31a is operated to a selective position where it goes too far. Thus, in the case where such going too far from the desired terminating selective position frequently occurs during the operation of the joystick knob 31a, it becomes necessary to return the joystick knob 31a to the normal desired terminating selective position every time the going too far occurs, and the character selection efficiency of the operation control device for character selection will be deteriorated as much.